chroot for aarch64

[Jan Palus]

For the last couple of days I've been boostrapping PLD for aarch64 and I'm happy
to report that my Pinebook Pro boots into PLD now (with just a little help from
Manjaro's kernel and wifi firmware). Basically everything works fine including,
but not limited to: rpm, poldek, X, Mesa, MATE, firefox, Qt5 apps, mpv.

In case anyone's interested I've created base chroot with some additional
packages so it's bootable and remotely accessible (systemd, openssh). Available
for download from GitHub:

https://github.com/jpalus/pld-linux-aarch64/releases

All packages built so far are available as poldek's repository (already
configured in chroot):

http://jpalus.fastmail.com.user.fm/dists/th/PLD/aarch64/RPMS/

Note that package list reflects my needs and you may not find what you're
looking for. However most of critical devel packages are there (ie gcc, llvm,
python, perl, ruby, rust, icedtea) making building new packages yourself smooth
and easy.

All fixes needed to build those packages are already committed to
git.pld-linux.org.